Use code ONREPEAT at checkout for 65% off up to $65 on Auto-Refill Orders.

Use code DOGDAY40 at checkout for $40 off your next order over $100.*

*Coupon terms and conditions: code DOGDAY40 applicable for one-time or Subscribe & Save orders, for a limited time. Coupon codes apply to many, but not all, products. Excluded products include but are not limited to Azodyl, Bravecto, Bravecto Plus, Droncit, Incurin, Mometamax, Numelvi, Optimmune, Posatex, Sentinel, Tri-Heart Plus, VetPen, Vetsulin, compounded and refrigerated medications. Promotional code valid through August 23, 2026.

Use code DOGDAY60 at checkout for $60 off your next order over $200.*

*Coupon terms and conditions: code DOGDAY60 applicable for one-time or Subscribe & Save orders, for a limited time. Coupon codes apply to many, but not all, products. Excluded products include but are not limited to Azodyl, Bravecto, Bravecto Plus, Droncit, Incurin, Mometamax, Numelvi, Optimmune, Posatex, Sentinel, Tri-Heart Plus, VetPen, Vetsulin, compounded and refrigerated medications. Promotional code valid through August 23, 2026.

Now Available on Koala: Royal Canin Vet Fresh Frozen Diets! Use code FRESH50 at checkout for 50% off your first Subscribe & Save order.*

*Coupon terms and conditions: code FRESH50 applicable for first-time Subscribe & Save orders only. Coupon code applies to the following products: Royal Canin Appetite Stimulation Fresh Frozen Dog Food, Royal Canin Gastrointestinal Low Fat Fresh Frozen Dog Food, and Royal Canin Selected Protein Pork Recipe Fresh Frozen Dog Food. Promotional code valid through December 31, 2026.

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Immune support supplements for dogs to help strengthen natural defenses. Trusted care from Koala Health.

Immune Support for Dogs

immune support

Cyclosporine (Atopica) is used to suppress the immune system to treat allergic skin and immune-mediated conditions.

Atopica for Dogs

Azathioprine is used to suppress the immune system to treat immune-mediated conditions.

Azathioprine

Diphenhydramine (Calmatrol) is an antihistamine used to treat allergic reactions and itchiness due to allergies.

Calmatrol

Cyclosporine (Cyclavance) is used to suppress the immune system to treat allergic skin and immune-mediated conditions.

Cyclavance

Cyclosporine is used to suppress the immune system to treat allergic skin and immune-mediated conditions.

Cyclosporine

Mycophenolate is used to suppress the immune system to treat immune-mediated conditions.

Mycophenolate

Prednisone and prednisolone are steroids used to treat a wide variety of dog illnesses including inflammatory conditions, immune-mediated diseases, certain cancers, and Addison's disease (hypoadrenocorticism).

Prednisone

Prednisone and prednisolone (PrednisTabs) are steroids used to treat a wide variety of dog and cat illnesses including inflammatory conditions, immune-mediated diseases, certain cancers, and Addison's disease (hypoadrenocorticism).

PrednisTabs

Diphenhydramine (Vetadryl) is an antihistamine used to treat allergic reactions and itchiness due to allergies.